(function($) {
  var cache = [],
      domain = 'http://static.timbertax.org/images/';
  
  $.preLoadImages = function() {
    var args_len = arguments.length;
    for (var i = args_len; i--;) {
      var cacheImage = document.createElement('img');
      cacheImage.src = domain + arguments[i];
      cache.push(cacheImage);
    }
  }
})(jQuery);

jQuery.preLoadImages('header-1.jpg','header-2.jpg','header-3.jpg','header-4.jpg','left-column-img-1.jpg','left-column-img-2.jpg','left-column-img-3.jpg','left-column-img-4.jpg');